$ { \left[\begin{array}{rr}{4} & {2} \\ {0} & {4} \\ {1} & {1}\end{array}\right]+\left[\begin{array}{rr}{2} & {3} \\ {0} & {-2} \\ {-2} & {-2}\end{array}\right] = {?} } $
To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{4}+{2} & {2}+{3} \\ {0}+{0} & {4}+{-2} \\ {1}+{-2} & {1}+{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{6} & {5} \\ {0} & {2} \\ {-1} & {-1}\end{array}\right]}$